JPH11289979A - O/w emulsion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an O/W emulsion having both resistance to refrigeration and thawing and resistance to heat, excellent in emulsion stability and useful for mayonnaise or the like by including an oil phase, the yolk of an egg treated with enzymes and an aqueous phase in respective specific contents. SOLUTION: This acidic O/W emulsion is produced by including (A) 8-50 wt.% oil phase containing triglyceride composed of one residue of a saturated fatty acid having 20C or more and two residues of an unsaturated fatty acid, in a quantity of 1.5 wt.% or more, (B) 1-15 wt.% yolk of an egg treated with enzymes such as phospholipase A and a protease such as bromelin and (C) 20-80 wt.% aqueous phase. The yolk of an egg treated with enzymes is pref. prepared by treating the yolk of an egg with phospholipase A and then by treating the yolk with a protease.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oil-in-water emulsion,
More specifically, acidic oil-in-water emulsions such as mayonnaise, tartar sauce, emulsified dressing, etc., and more specifically, oil-in-water emulsions that are stable after freezing and thawing even when further heated, have freeze-thaw resistance and heat resistance. The present invention relates to an acidic oil-in-water type emulsion having a combination.

[0002]

2. Description of the Related Art As a seasoning for foods, oil-in-water oils such as mayonnaise, tartar sauce, emulsified dressing, etc. made mainly from oils and fats, egg ingredients such as egg yolk, whole eggs and egg whites, vinegar and seasonings. There are type emulsions, which are widely used in eating out, salads and other prepared foods, confectionery, baking industry and the like. By the way, in recent years, a variety of frozen foods have been developed and marketed due to the progress of food freezing technology and the spread of microwave ovens. Some of these frozen foods include meat and seafood and seasonings such as mayonnaise, tartar sauce, emulsified dressing, etc., as in frozen fried food, which are then put on clothes and frozen, or mayonnaise and tartar in advance. There are some which are seasoned with sauce, emulsified dressing or the like and then frozen. These foods are very convenient because they can be eaten only by frying in a frozen state, baking in an oven, or heating in a microwave oven.

[0003] However, in an acidic oil-in-water emulsion such as ordinary mayonnaise, tartar sauce, and emulsion dressing,
It is presumed that this is due to the freeze denaturation of the raw materials used during thawing after frozen storage, especially egg raw materials.However, the oil-in-water emulsion stability becomes unstable, and when heated from a frozen state at a stretch, the water content is reduced. The oil-in-water emulsification is destroyed by the rise or the heat denaturation of the raw materials, resulting in a problem that oil is separated and the appearance, texture and flavor of the food are significantly impaired. In particular, in the case of heating in a microwave oven, there is a problem that the temperature of the product rapidly rises in a few minutes due to the microwave, so that the evaporation of water is remarkable, and the heat denaturation also occurs rapidly, so that the oil-in-water emulsion is more easily destroyed. .

[0004] As means for solving these problems, various oil-in-water emulsions have been proposed. For example,
A method of adding a phospholipase protein denatured by phospholipase A (Japanese Patent Publication No. 53-44426), a method of emulsifying an aqueous raw material and an oily raw material using trypsin-treated partially hydrolyzed egg yolk (Japanese Patent Publication No. 5-47)
186) and a method of using extremely hardened oil as a part of the oil phase raw material (Japanese Patent Publication No. 62-25340).

However, these methods also have good freeze-thaw resistance when the freezing period is as short as several weeks, but the longer the freezing period is, the longer the freezing and denaturation of the raw materials used are. However, the oil-in-water emulsion stability was destabilized, and the oil tended to separate after freezing and thawing. Furthermore, the oil-in-water emulsification is remarkably destroyed by the subsequent heating and the oil is separated, so that it is still insufficient in satisfying both the freeze-thaw resistance and the heat resistance.

[0006]

Accordingly, an object of the present invention is to provide an oil-in-water type emulsion having a relatively high water content, even when used for frozen foods having a long freezing period, when frozen and thawed. Oil-in-water emulsions are stable, and oil-in-water emulsions are stable even if subsequently heated and oil separation does not occur, especially acidic oil-in-water emulsions such as mayonnaise, tartar sauce, and emulsion dressing It is to provide an emulsion.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies and studies to solve the above-mentioned problems concerning acidic oil-in-water emulsions such as mayonnaise, tartar sauce, emulsified dressing and the like. It has been found that the above object can be achieved by combining raw materials.

[0008] The present invention has been made based on the above findings, comprising 8 to 50% by weight of an oil phase and 1 to 15% by weight of an enzyme-treated egg yolk.
An oil-in-water emulsion characterized by containing 20 to 80% by weight of an aqueous phase.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the oil-in-water emulsion of the present invention will be described in detail. Fats and oils are used as the oil phase used in the present invention. The fats and oils may be any edible fats and oils, such as soybean oil, rapeseed oil, corn oil, cottonseed oil, olive oil, peanut oil, rice oil, and beniflower Oils and liquids at room temperature such as sunflower oil are common, but oils and fats that are solid at room temperature such as palm oil, palm kernel oil, coconut oil, monkey fat, mango fat, and milk fat are not excluded. Further, fats and oils which have been subjected to physical or chemical treatment such as hardened oil, fractionated oil, and transesterified oil can be used.

A preferred oil phase is an oil phase containing 1.5% by weight or more of a triglyceride comprising one residue of a saturated fatty acid having 20 or more carbon atoms and two residues of an unsaturated fatty acid, and more preferably 20% or more. An oil phase containing 3% by weight or more of a triglyceride composed of one residue of a saturated fatty acid and two residues of an unsaturated fatty acid. Examples of the saturated fatty acid having 20 or more carbon atoms in the present invention include arachiic acid, behenic acid, lignoceric acid and the like. Examples of the unsaturated fatty acid include oleic acid, linoleic acid and linolenic acid, but are not particularly limited. The binding position of the saturated fatty acid residue having 20 or more carbon atoms may be any of the first, second, and third positions of triglyceride.

For example, in a salad oil whose oil phase is usually used for mayonnaise and dressings, the water phase solidifies during freezing and expands in volume, so that the liquid oil phase is pressed and deformed. Because of aggregation, the oil phase is easily separated during thawing. On the other hand, when the oil phase is mixed with a triglyceride comprising one residue of a saturated fatty acid having 20 or more carbon atoms and two residues of an unsaturated fatty acid, the oil phase becomes fine crystals during freezing, and the water phase solidifies. Even if the oil phase expands, the oil phase is kept as fine crystals and does not deform. Therefore, when the oil phase is thawed, the oil phase only melts and the emulsification is not destroyed.

In order to obtain an oil or fat containing 1.5% by weight or more of the above triglyceride which forms the above preferable oil phase,
It can be obtained by separating rapeseed oil, peanut oil, fish oil, monkey fat, mustard oil, mango fat and using the low melting point portion, or transesterifying these fats or oils, or by synthesis. By the method as described above, fats and oils containing 1.5% by weight or more of triglyceride composed of one residue of a saturated fatty acid having 20 or more carbon atoms and two residues of an unsaturated fatty acid can be obtained, and rapeseed oil, peanut oil, fish oil, Fats and oils such as monkey fat, mustard oil and mango fat contain about 1.1% by weight of a triglyceride comprising one residue of a saturated fatty acid having 20 or more carbon atoms and two residues of an unsaturated fatty acid. Therefore, natural fats and oils cannot be used as they are.

When the oil phase containing 1.5% by weight or more of triglyceride composed of one residue of a saturated fatty acid having 20 or more carbon atoms and two residues of an unsaturated fatty acid is used as the oil phase in the present invention, One or more fats or oils containing 1.5% by weight or more of a triglyceride comprising one residue of a saturated fatty acid having 20 or more carbon atoms and two residues of an unsaturated fatty acid obtained by the above method are mixed together to form an oil phase. Or mixed with other edible fats and oils, and the mixed oil contains 1.5% by weight or more of triglyceride composed of one residue of a saturated fatty acid having 20 or more carbon atoms and two residues of an unsaturated fatty acid. You may do so. In addition, components or additives soluble in fats and oils such as an antioxidant such as tocopherol and a coloring agent such as β-carotene may be added to the oil phase.

The mixing ratio of the above oil phase is from 8 to 50% by weight, preferably from 15 to 40% by weight, in order to stabilize the oil-in-water emulsification and to improve the flavor and texture. When the blending ratio of the oil phase is more than 50% by weight, the oil-in-water emulsion becomes unstable, and when it is less than 8% by weight, the texture of the obtained oil-in-water emulsion, particularly the acidic oil-in-water emulsion becomes poor.

Next, in the present invention, egg yolk treated with an enzyme is used as an emulsifier. When an egg yolk not treated with an enzyme is used, the resulting oil-in-water emulsion, particularly an acidic oil-in-water emulsion, has poor freeze-thaw resistance and heat resistance. Enzyme-treated yolks include raw yolk, sterilized yolk, salted yolk,
Any of sweetened egg yolks can be used, but salted egg yolk is suitable in consideration of the flavor of the resulting oil-in-water emulsion and suppressing the growth of microorganisms during the enzymatic reaction. % Salted egg yolk is preferably used, and more preferably salted egg yolk added with 5 to 8% by weight of salt.

In the present invention, the enzyme used in the enzyme treatment is preferably a combination of phospholipase A and a protease. Phospholipase A is also called a phospholipid hydrolase and is an enzyme that catalyzes a reaction for decomposing phospholipids into lysophospholipids. Phospholipase A ₁ (EC3.1) depends on the position of an acting ester bond. .1.3
2) and phospholipase A ₂ (EC 3.1.1.4)
And pancreatic juice of mammals such as pigs, and commercially available phospholipase A derived from microorganisms can be used. Proteases are enzymes that catalyze the reaction of hydrolyzing proteins, and are enzymes derived from plants, animals and microorganisms, such as bromelain derived from pineapple, papain derived from papaya, and pancreatic fluid derived from mammals. Trypsin, pepsin derived from mammalian gastric juice, mold-derived protease, etc.
Commercially available proteases can be used, especially bromelain.

When the yolk is enzymatically treated, phospholipase A
The addition of the protease and the protease can be performed in any order or at the same time, but in order to avoid the hydrolysis of phospholipase A by the protease, it is preferable that the egg yolk is subjected to the enzyme treatment with the phospholipase A and then the enzyme treatment with the protease.

As these enzymes, commercially available powdery or liquid enzymes for food can be used.

The amount of phospholipase A added was 1 g of egg yolk.
However, it is preferable that an amount corresponding to the activity of 0.2 to 100 phospholipase units, more preferably 0.5 to 20 phospholipase units, is applied.
The phospholipase unit is a unit indicating the amount of phospholipase activity, and one phospholipase unit is expressed in the yolk when phospholipase A is allowed to act on the yolk at pH 8.0 and 40 ° C. It is the amount of activity that releases 1 micromole of fatty acids per minute from phospholipids. The amount of the protease added is preferably 0.1 to 1 g of egg yolk.
01 to 10 protease units, more preferably 0.1 to 10 protease units.
It is preferable to apply an amount corresponding to the activity amount of 1 to 5 protease units. Protease unit is pH
It is an activity amount showing a color degree corresponding to 1 micromol of tyrosine per minute when a protease is allowed to act on milk casein at 7.0 and 37 ° C.

The above enzyme comprising a combination of phospholipase A and a protease may be added according to the following criteria. That is, the addition amount (total amount) of the enzyme is 1 egg yolk.
The amount is preferably 0.001 to 0.8 parts by weight, more preferably 0.01 to 0.3 parts by weight, based on 00 parts by weight. At this time, the weight ratio of phospholipase A to protease is preferably 20/80 to 90/10,
More preferably, it is 40/60 to 85/15.

The enzyme treatment of egg yolk is preferably carried out at an optimum temperature of phospholipase A and protease, without denaturation of the protein, phospholipase A and protease of the egg yolk by heat, and is usually 20 to 60 ° C., more preferably 20 to 60 ° C. 40-55
It is good to perform in the temperature range of ° C. Further, it is advantageous to carry out stirring with a stirrer or the like during the enzyme treatment. The reaction time for the enzyme treatment of egg yolk is not particularly limited, but it is preferable to carry out the reaction within the range of 1 to 30 hours. In addition, as a method of enzymatic treatment of egg yolk, a method of hydrolyzing in a batch system under the above-described conditions is adopted, but a method of hydrolyzing in a continuous system may be used.

It is preferable to adjust the pH of the phospholipase A and the protease to the optimal pH during the enzyme treatment of the egg yolk. The pH adjuster for this purpose is not particularly limited as long as it is for food.
For example, acidulants such as lactic acid, citric acid, gluconic acid, adipic acid, succinic acid, tartaric acid, fumaric acid, malic acid, phosphoric acid, ascorbic acid, acetic acid, and sodium dihydrogen phosphate,
Acidic substances such as potassium dihydrogen phosphate, vinegar, fruit juice, fermented milk, sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium citrate, sodium acetate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, phosphorus Trisodium acid, sodium ascorbate and the like can be used, and for example, it is preferably carried out in a pH range of 6 to 9. In addition, during the enzyme treatment of egg yolk, a calcium salt such as calcium chloride for food and calcium dihydrogen phosphate may be added as a stabilizer for the enzyme.

The degree of degradation of the yolk phospholipids into lysophospholipids by phospholipase A and the degree of hydrolysis of egg yolk proteins by proteases depend on the amount of enzyme added, reaction temperature, pH at the start of the reaction, It is affected by the presence or absence of the stabilizer, the reaction time, etc., but is not particularly limited. For example, the degree of decomposition of the phospholipid of egg yolk into lysophospholipid by phospholipase A is 30 to 1 of the total phospholipid contained in egg yolk.
Preferably, the protein is degraded to an extent that 00% by weight is decomposed into lysophospholipid, and the degree of hydrolysis of the protein of the yolk by the protease is degraded to such an extent that the protein contained in the yolk is completely lost to heat coagulation. Is preferred.

The mixing ratio of the above-mentioned enzyme-treated egg yolk is from 1 to 1 in order to stabilize oil-in-water emulsification and to improve flavor and texture.
It is 5% by weight, preferably 3 to 12% by weight. When the blending ratio of the enzyme-treated egg yolk is more than 15% by weight, the viscosity of the obtained oil-in-water emulsion, particularly the acidic oil-in-water emulsion is significantly increased, and when it is less than 1% by weight, the oil-in-water emulsion becomes unstable. is there.

In the oil-in-water emulsion of the present invention, the mixing ratio of the aqueous phase is 20 to 80% by weight, preferably 50 to 70% by weight. The oil-in-water emulsion of the present invention is stable even in such a state where the ratio of the aqueous phase is high, and has excellent freeze-thaw resistance and heat resistance, and is particularly suitable as an acidic oil-in-water emulsion. In preparing the oil-in-water emulsion of the present invention,
The aqueous phase is prepared including the enzyme-treated egg yolk,
The enzyme-treated egg yolk at this time is not included in the mixing ratio of the aqueous phase.

Therefore, the aqueous phase in the present invention contains acidulants, thickening stabilizers, modified starches, modified starches, seasonings, and spices which are usually used in acidic oil-in-water emulsions such as mayonnaise, tartar sauce, emulsified dressing and the like. Auxiliary materials such as perfumes, salt, sugars, dextrin, milk protein, coloring agents and the like can be arbitrarily used as long as the object of the present invention is not impaired. For example, acidulants include lactic acid, citric acid, gluconic acid, adipic acid, succinic acid, tartaric acid, fumaric acid, malic acid, ascorbic acid, vinegar, fruit juice, fermented milk and the like, and as a thickening stabilizer xanthan gum, alginic acid sodium,
Guar gum, tarragant gum, locust bean gum,
Gellan gum, gelatin, microfibrous cellulose and the like, as modified starch, corn, waxy corn,
Tapioca, potato, sweet potato, wheat, rice, etc. originated from starch and treated with enzymes such as amylase,
Acid and alkali, esterification, phosphoric acid cross-linking, heating, such as those subjected to physical and chemical treatments such as heat and moisture,
Further, there may be mentioned those obtained by preliminarily gelatinizing these modified starches by heat treatment so as to be easily dissolved in water.

The oil-in-water emulsion of the present invention can be obtained, for example, as follows. First, the enzyme-treated egg yolk in water,
An aqueous phase is prepared by dispersing and dissolving an acidulant such as vinegar, salt, sugar such as starch syrup, and a spice such as pepper. The aqueous phase is obtained by dispersing modified starch and a thickening stabilizer in soybean oil. Next, the oil phase is added while stirring the water phase to obtain an oil-in-water type pre-emulsion. This is treated with an emulsifier such as a colloid mill or a homogenizer such as a homogenizer to perform finish emulsification, whereby the oil-in-water emulsion of the present invention is obtained.

[0028]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, which do not limit the present invention in any way.

Example 1 Salted egg yolk containing 7% by weight of salt was adjusted to pH 8.5 with sodium hydroxide, and 100,000 kg of the phospholipase A derived from porcine pancreatic juice was converted to 600,000 phospholipase. Unit plus 4
Treatment at 5 ° C. for 4 hours, then bromelain 20000
0 units were added, and reacted at 45 ° C for 7 hours.
The mixture was cooled to obtain an enzyme-treated egg yolk. Water 31% by weight, starch syrup (water 30% by weight) 10% by weight, vinegar 6% by weight, salt 1.8% by weight, sodium glutamate 0.2% by weight,
An aqueous phase was prepared by mixing 10% by weight of the enzyme-treated egg yolk. Separately, an oil phase was prepared by mixing 40% by weight of soybean oil and 1% by weight of modified starch obtained by gelatinizing waxy corn after phosphoric acid crosslinking. Next, the oil phase was added while stirring the aqueous phase to obtain an oil-in-water type pre-emulsion, which was emulsified by a colloid mill to obtain an oil-in-water type emulsion of the present invention. This oil-in-water emulsion 10
0 g was sealed in a polyethylene bag, frozen at -20 ° C and thawed at room temperature two months later, and subsequently opened and examined after heating in a microwave oven with high frequency output of 500 W for 60 seconds. Was. The results are shown in Table 1 below.

Comparative Example 1 31% by weight of water, syrup (water 3
0% by weight), 10% by weight of vinegar, 1.8% by weight of salt, 0.2% by weight of sodium glutamate, 7% by weight, and 10% by weight of salted egg yolk were mixed to prepare an aqueous phase. Separately, an oil phase was prepared by mixing 40% by weight of soybean oil and 1% by weight of modified starch obtained by gelatinizing waxy corn after phosphoric acid crosslinking. Next, the oil phase was added while stirring the water phase to obtain an oil-in-water type pre-emulsion, which was emulsified by a colloid mill to obtain an oil-in-water type emulsion. 100 g of the oil-in-water emulsion was sealed in a polyethylene bag, frozen at −20 ° C., thawed at room temperature two months later, and then opened to obtain a high-frequency output of 50 μm.
The state after the heat treatment in a microwave oven of 0 W for 60 seconds was examined. The results are shown in Table 1 below.

Example 2 52.8% by weight of water, 12% by weight of syrup (30% by weight of water), 7% by weight of vinegar, 1.8% of salt
% Of sodium glutamate, 0.2% by weight of coarsely ground pepper, and 8% by weight of the same enzyme-treated egg yolk as used in Example 1 to prepare an aqueous phase. Separately, an oil phase was prepared by mixing 15% by weight of rapeseed salad oil and 3% by weight of modified starch obtained by gelatinizing waxy corn after crosslinking with phosphoric acid. Next, the oil phase was added while stirring the water phase to obtain an oil-in-water type pre-emulsion, which was homogenized with a homogenizer to obtain the oil-in-water type emulsion of the present invention. This oil-in-water emulsion 10
0 g was sealed in a polyethylene bag, frozen at -20 ° C and thawed at room temperature two months later, and subsequently opened and examined after heating in a microwave oven with high frequency output of 500 W for 60 seconds. Was. The results are shown in Table 1 below.

Comparative Example 2 52.8% by weight of water, 12% by weight of syrup (30% by weight of water), 7% by weight of vinegar, 1.8% of salt
An aqueous phase was prepared by mixing 0.2% by weight of sodium glutamate, 0.2% by weight of coarsely ground pepper and 8% by weight of salted egg yolk. Separately, an oil phase was prepared by mixing 15% by weight of rapeseed salad oil and 3% by weight of modified starch obtained by gelatinizing waxy corn after crosslinking with phosphoric acid. Next, the oil phase was added while stirring the water phase to obtain an oil-in-water type pre-emulsion, which was homogenized with a homogenizer to obtain the oil-in-water type emulsion of the present invention. 100 g of the oil-in-water emulsion was sealed in a polyethylene bag, frozen at −20 ° C., thawed at room temperature two months later, and subsequently opened and opened to obtain a high-frequency output of 500 W
The state after the heat treatment in the microwave oven for 60 seconds was examined. The results are shown in Table 1 below.

Example 3 23.8% by weight of water, 10% by weight of starch syrup (30% by weight of water), 7% by weight of vinegar, 1.8% of salt
% By weight, sodium glutamate 0.2% by weight, ground pepper 0.1% by weight, egg flavor 0.1% by weight, and the same enzyme-treated egg yolk 12% by weight as used in Example 1 were mixed to form an aqueous phase. Prepared. Separately, 45% by weight of rapeseed salad oil was used as the oil phase. While stirring the aqueous phase, the oil phase was added to obtain an oil-in-water type pre-emulsion, which was homogenized with a homogenizer to obtain the oil-in-water type emulsion of the present invention. 100 g of this oil-in-water emulsion was sealed in a polyethylene bag, frozen at -20 ° C, thawed at room temperature two months later, and then opened and heated in a microwave oven with high frequency output of 500 W for 60 seconds. The state after the treatment was examined. The results are shown in Table 1 below.

Example 4 A salted egg yolk containing 8% by weight of sodium chloride was adjusted to pH 8.0 with sodium hydroxide, and 100,000 of this was supplemented with 300,000 phospholipase A derived from porcine pancreatic juice. Unit plus 4
Treat at 5 ° C. for 5 hours, then bromelain 80000
Add the unit and react at 45 ° C for 10 hours.
The mixture was cooled to obtain an enzyme-treated egg yolk. 23.8% by weight of water,
10% by weight of starch syrup (30% by weight of water), 7% by weight of vinegar, 1.8% by weight of salt, 0.2% by weight of sodium glutamate, 0.1% by weight of ground pepper, 0.1% of egg flavor
By weight, 12% by weight of the above-mentioned enzyme-treated egg yolk was mixed to prepare an aqueous phase. Separately, 45% by weight of rapeseed salad oil was used as the oil phase. While stirring the aqueous phase, the oil phase was added to obtain an oil-in-water type pre-emulsion, which was homogenized with a homogenizer to obtain the oil-in-water type emulsion of the present invention. 100 g of this oil-in-water emulsion was sealed in a polyethylene bag, frozen at -20 ° C, thawed at room temperature two months later, and then opened and heated in a microwave oven with high frequency output of 500 W for 60 seconds. The state after the treatment was examined. The results are shown in Table 1 below.

Example 5 31% by weight of water, syrup (water 3
0% by weight) 10% by weight, 6% by weight of vinegar, 1.8% by weight of sodium chloride, 0.2% by weight of sodium glutamate, and 10% by weight of the same enzyme-treated egg yolk as used in Example 1 were mixed to form an aqueous phase. Prepared. Separately, 10% by weight of a pre-melted fractionated oil of low melting point of monkey fat (melting point 10 ° C., iodine value 60, containing about 10% by weight of triglyceride composed of one residue of arachiic acid and two residues of oleic acid) and 30% of soybean oil % By weight, modified starch obtained by gelatinizing waxy corn starch after crosslinking with phosphoric acid 1
The oil phase was prepared by mixing the weight%. Next, the oil phase was added while stirring the aqueous phase to obtain an oil-in-water type pre-emulsion, which was emulsified by a colloid mill to obtain an oil-in-water type emulsion of the present invention. 100 g of the oil-in-water emulsion was sealed in a polyethylene bag, frozen at −20 ° C., thawed at room temperature two months later, and subsequently opened and opened to obtain a high-frequency output of 500 W
The state after the heat treatment in the microwave oven for 60 seconds was examined. The results are shown in Table 1 below.

Example 6 23.8% by weight of water, 10% by weight of starch syrup (30% by weight of water), 7% by weight of vinegar, 1.8% of salt
% By weight, 0.2% by weight of sodium glutamate, 0.1% by weight of coarsely ground pepper, 0.1% by weight of egg flavor, and 12% by weight of the same enzyme-treated egg yolk as used in Example 4 to form an aqueous phase. Prepared. Separately, random transesterification oil of 5% by weight of extremely hardened oil of high erucic acid rapeseed oil (the ratio of erucic acid is 40% by weight or more) and 95% by weight of soybean salad oil (one residue of behenic acid, oleic acid, linoleic acid, and linolenic acid) An oil phase was prepared by mixing 5% by weight of a triglyceride comprising 2 residues of any one of the unsaturated fatty acids of the acid) and 40% by weight of rapeseed salad oil. Next, the oil phase was added while stirring the water phase to obtain an oil-in-water type pre-emulsion,
This was emulsified in a colloid mill to obtain an oil-in-water emulsion of the present invention. 100 g of this oil-in-water emulsion was sealed in a polyethylene bag, frozen at -20 ° C., thawed at room temperature two months later, and then opened to obtain a high-frequency output of 5
The state after the heat treatment in a 00 W microwave oven for 60 seconds was examined. The results are shown in Table 1 below.

[0037]

[Table 1]

[Examples 7 to 10] In the same manner as in Examples 1 to 3, except that the enzyme-treated egg yolk obtained in the following manner was used instead of the enzyme-treated egg yolk used in Examples 1 to 3. Oil-in-water emulsions of the present invention were obtained (Examples 7 to 10).
9). A salted egg yolk containing 7% by weight of salt was adjusted to pH 8.5 with sodium hydroxide, and 0.01 part by weight of phospholipase A derived from porcine pancreatic juice was added to 100 parts by weight of the salted egg yolk. For 7 hours, and then added with 0.002 parts by weight of bromelain, reacted at 45 ° C. for 5 hours, and cooled to 10 ° C. to obtain enzyme-treated egg yolk.

The oil-in-water emulsion of the present invention was prepared in the same manner as in Example 4 except that the enzyme-treated egg yolk obtained in the following manner was used instead of the enzyme-treated egg yolk used in Example 4. (Example 10). A salted egg yolk containing 8% by weight of salt was adjusted to pH 8.0 with sodium hydroxide.
Phospholipase A derived from porcine pancreatic juice per 100 parts by weight
, And treated at 50 ° C. for 3 hours.
The mixture was reacted at 0 ° C. for 3 hours and cooled to 10 ° C. to obtain an enzyme-treated egg yolk.

The oil-in-water emulsions obtained in Examples 7 to 10 were evaluated in the same manner as in Examples 1 to 4, and as a result, completely the same effects were obtained.

[0041]

The oil-in-water emulsion of the present invention has both freeze-thaw resistance and heat resistance, and is particularly suitable as an acidic oil-in-water emulsion for use in frozen foods. The oil-in-water emulsion of the present invention, particularly by using egg yolk treated with phospholipase A and protease as a raw material, even when heated at a stretch by a microwave oven or the like from a frozen and thawed state, which was conventionally difficult. In addition, an oil-in-water type emulsion having stable oil-in-water type emulsion can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takashi Suzuki 7-35 Higashiogu, Arakawa-ku, Tokyo Asahi Denka Chemical Industry Co., Ltd.

Claims (6)

[Claims] 1. Oil phase 8-50% by weight, enzyme-treated egg yolk 1
An oil-in-water emulsion comprising 15% by weight and 20 to 80% by weight of an aqueous phase. 2. The oil-in-water emulsion according to claim 1, wherein the enzyme-treated egg yolk is an enzyme-treated egg yolk obtained by treating egg yolk with phospholipase A and a protease. 3. The oil-in-water type according to claim 1, wherein the enzyme-treated egg yolk is an enzyme-treated egg yolk obtained by treating egg yolk with phospholipase A and then with protease. Emulsion. 4. The oil-in-water emulsion according to claim 1, wherein the protease is bromelain. 5. The method according to claim 1, wherein the oil phase is a saturated fatty acid 1 having 20 or more carbon atoms.
The triglyceride comprising a residue and two unsaturated fatty acids is contained in an amount of 1.5% by weight or more.
5. The oil-in-water emulsion according to any one of items 1 to 4. 6. The oil-in-water emulsion according to claim 1, which is an acidic oil-in-water emulsion.